Supercharging means



y 18, 1954 e. A. scmocco SUPERCHARGING MEANS Filed June 10, 1955 Patented May 18, 1954 UNI STATES PATENT OFFICE My invention relates particularly to internal combustion engines, pumps, and the like, which have as elements thereof a cylinder and a piston reciprocating therein.

The principal object of my invention is to provide an improvement in internal combustion engines, particularly of the four-cycle type, reciprocating pumps, and the like, whereby the volume of the fluid drawn into the cylinder on the intake stroke of the piston is increased beyond that produced by the normal displacement of the piston. Another object. of my invention is to provide an auxiliary cylinder with a piston therein which is reciprocated in timed relation to the piston in the main cylinder to increase the volume of the space into which the fluid is drawn on the intake stroke of the main piston but which is so disposed with respect to the travel of the main piston that, during the compression stroke thereof, the auxiliary piston is not subjected to appreciable compression force. More specifically, one of the objects of my invention is to provide a device of this character in which the auxiliary cylinder communicates with the main cylinder through a port in the side of the main cylinder in a zone which is traversed by the main piston and, in the case of an internal combustion engine, which is below the midpoint of the path of travel of the main piston. Thus, the auxiliary cylinder communicates with the main cylinder during only a portion of the lower half of the main piston travel. In other words, the intake volume of the main cylinder is not increased until the piston passes the port through which the auxiliary cylinder communicates with the main cylinder. As the main piston moves upwardly on the compression stroke, the piston in the auxiliary cylinder forces the contents thereof into the main cylinder before communication between said cylinders is cut off by the L movement of the main piston past said port.

I accomplish these and other objects as will be apparent as the description proceeds by the means described below and illustrated in the accompanying drawing, in which Fig. l is a fragmentary side elevation of an internal combustion engine equipped with my device;

Fig. 2 is a fragmentary top plan view of the engine;

Fig. 3 is an enlarged section of Fig. 1 in the plane 3-3 showing the main piston shortly after it has passed the mid point of its travel;

Fig. 4 is a view similar to Fig. 3 showing the main piston at the bottom of its intake stroke;

Fig. 5 is section of Fig. 1 in the plane 5+5; and

Fig. 6 is a vertical axial section through the port which provides communication between the main cylinder and the auxiliary cylinder showing a modified type of closure for said passage.

Referring to the drawing, I have chosen to -illustrate my invention in connection with an ordinary four-cycle internal combustion engine, but it will be apparent from the followingdescription that my invention is just as applicable to pumps or other devices comprising a cylinder and a piston reciprocating therein in which it is desirable to increase the volume of the intake beyond that resulting from the normal displacement of the piston.

As illustrated, I is a main cylinder here illustrated as a sleeve which is surrounded by a water jacket 2. 3 is the main piston having the connecting rod 4 connected to the wrist pin 5 and to the crank 6 on the main shaft 1. 8 is an intake valve and 9 is an exhaust valve. Extending through the side of the cylinder and water jacket is a sleeve forming a port II] which provides communication between the main cylinder I and the auxiliary cylinder II which is shown as secured to the side of the main cylinder and water jacket by cap screws I2. A piston I3 is mounted to reciprocate in the cylinder II between the position shown in Fig. 3 and that shown in Fig. 4. This piston is provided with an extension I4 which moves in and out of the port ID. The extension I l may have a cross sectionsuch as that shown in Fig. 5, or the port may be tapered and the extension frusto-conical, as shown at I5 in Fig. 6. After the extension I4 has entered the port, it must be so designed that itwill not completely seal the port until the piston I3 has reached the end of its stroke to the left, otherwise the contents of thecylinder II could not be forced into the main cylinder through the port. An extension such as that shown in Fig. 5 never completely seals the port, but that shown in Fig. 6 does close the port when the piston I3 is at the end of its stroke to the left. In order that the piston I3 may be moved freely to the right by means of the spring I6, the cylinder II is provided with air vents H as shown in Figs. 3 and 4.

I8 is a cam shaft, which is understood to be driven by means (not shown) from the main crank shaft I, on which are cams I9 cooperating with the rocker arms 2!] for controlling the movements of the pistons I3. This may be a separate cam shaft but, as illustrated, is the same shaft on which the cams 2| cooperating with the push rods 22, which actuate the intake and exhaust valves, are located.

As illustrated, it will be apparent from Fig. 3 that the follower 20 is about to drop into the depression 23 in the cam is and thus allow the piston I3 to move from the position shown in Fig. 3 to that shown in Fig. 4, thus opening the port In after the main piston 3 has passed the mid-point of its intake stroke. In the case of an internal combustion engine, the charge being drawn into the cylinder I by the piston 3 can then pass through the port I into the cylinder II or, in the case of a pump, the fluid or liquid drawn into the main cylinder I by the intake stroke of the piston 3 may pass into the cylinder II thus increasing the volume of the charge-re ceiving space produced by the displacement of the piston 3 on its intake stroke by the volume of the cylinder I I. As illustrated, the crank 6 is about 60 from its lower dead center when the port I0 begins to open, and the piston I3 will be moved to the left to force the contents of the cylinder II into the main cylinder I after the crank 8 passes its lower dead center, and the piston I3 will return from the position shown in Fig. 4 to that shown in Fig. 3 before the main piston 3 seals the port It on its upward or compression stroke. As shown, the port I0 will be completely sealed by the piston 3 when the crank 6 is about 60 past its lower dead center.

It will be apparent, however, that the location of theport III with respect to the space traversed by the piston 3 is not too material so long as it communicates with the main cylinder within the path of movement of the main piston 3, although it must be high enough above the position of the piston 3 when .at its lowest point to provide time for the introduction of a charge into the cylinder II, and its expulsion therefrom into the main cylinder before the port It is closed by the up ward movement of the main piston.

It will also be apparent that the particular type of valves which are employed to admit fluid into the main cylinder I and to exhaust it therefrom is substantially immaterial insofar as the invention is concerned, and hence the invention may be applied not only to internal combustion engines, but to pumps and the like, which comprise a main cylinder and a piston reciprocating therein.

While I have described my invention in connection with a standard four-cycle internal combustion engine, it is to be understood that the words which I have used are words of description merely to illustrate how the invention functions, and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of my invention.

I claim:

1. An internal combustion engine comprising a main cylinder; a power piston mounted to reciprocate therein; means for passing a combustible charge into said cylinder during an intake movement of said power piston; a second cylinder having a piston therein and communicating with said main cylinder in a zone below the mid point of the travel of said power piston; and means cooperating with the piston in said second cylinder in timed relation to the movements of said power piston for reciprocating said second piston; said second piston moving away from said main cylinder during an intake movement of said power piston to increase the volume of the space into which a charge may be introduced into said main cylinder, and towards said main cylinder to force the combustible gas in said second cylinder into said main cylinder before the power piston moves past said zone on its compression stroke.

2. An internal combustion engine comprising a main cylinder; a power piston mounted to reciprocate therein; means for passing a combustible charge into said cylinder during an intake movement of said power piston; a second cylinder having a piston therein and communicating with said main cylinder through a passage in the side of said main cylinder below the mid-point of the travel of said power piston; a rod on said second piston adapted to reciprocate in said passage and substantially close the same when entirely with in said passage; and means cooperating with the piston in said second cylinder in timed relation to the movements of said power piston for reciprocating said second piston; said second piston moving away from said main cylinder during an intake movement of said power piston to increase the volume of the space into which a charge may be introduced into said main cylinder, and towards said main cylinder to force the combustible gas in said second cylinder into said main cylinder before the power piston moves past said zone on its compression stroke.

3. In a device comprising a main cylinder, a main piston mounted to reciprocate therein, a valve for admitting fluid to said cylinder, and a valve for exhausting fluid therefrom; means for increasing the fluid capacity of said cylinder, beyond that resulting from the normal displacement of said main piston, during an intake stroke thereof; said means comprising an auxiliary cylinder communicating with said main cylinder through a port in the side of said main cylinder in a zone traversed by said main piston; a piston in said auxiliary cylinder and means for reciprocating said last mentioned piston in timed relation to the movements of said main piston to open said port and place said auxiliary cylinder in communication with said main cylinder during an intake stroke of said main piston, and to close said port shortly after said main piston ends its intake stroke.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 18,003 Zeman Mar. 1'7, 1931 1,087,841 Sitzler Feb. 17, 1914 1,274,226 Wolfram July 30, 1918 1,557,710 Lennon Oct. 20, 1925 FOREIGN PATENTS Number Country Date 270,126 Italy Dec. 19, 1929 

